Copy the contents of one file to another file, resulting in two copies of the same file on your account.

cp oldfilename newfilename

Copy the contents of one directory to another directory. Make sure you have created the destination directory before trying to copy files to it - see mkdir above. Results in two copies of the files on your account; one copy in the existing directory and another in the destination directory.

The find command can be used to locate files or a group of files. It can also be used to display directories. The example given will find all file and directory names within the current directory and subdirectories of it that begin with the letter n. (You can also explore using the locate command - type info locate and/or man locate for usage information.)

find -name ‘n*’

Can be used to locate text in a specific file or directory of files (use * in place of filename to search all of the files in the current directory). The -i argument indicates the search is to disregard cASe, the -n instructs to show the corresponding line number, and -w tells it to match only based on the whole word. (This doesn’t even begin to touch on the power of grep and its many uses. In addition to its searching capability, the grep command can be used in combination with other commands to act as a filter. It also allows the use of “wildcards”. Two other variations of grep are also available, egrep and fgrep. To begin your quest for more information, type man grep and/or info grep.)

Use to rename a file (mv fileA fileB), move a file (mv fileA /dirA/), or both (mv fileA /dirB/fileB).

mv oldfilename newfilename

Removes (deletes) the specified file. (The -i is not necessary, but is recommended as it will prompt you to confirm the action first. When prompted, type y to confirm or type n if you changed your mind.)

To archive a directory and all of its contents including subdirectories, navigate to where the directory is located and type the above command, replacing filename.tar with the name you wish to give the archive file and directoryname with the name of the directory you wish to archive. Alternatively, you can archive a select group of individual files (or directories) by specifying each file name in place of directoryname separated by spaces, like tar -cvf filename.tar fileA fileB fileC. Note: When creating a tar file (aka “tarball”) be sure to specify the name you wish to give the tar file! (TAR indicates Tape ARchive, as it was originally a tape archiving program. The -c means “create”, v means “verbose” (which basically says tell me what you’re doing), and the f indicates that a filename will follow (filename.tar)).

tar -cfv filename.tar directoryname

Typing this command will result in a list of the contents of the tar file. This is generally a good thing to do before unpacking the tar file to be sure there are no matching filenames which will result in files being unintentionally overwritten.

tar -tvf filename.tar

You can see the similarities to the command used to tar the file. This time, though, you use -x to “extract” instead of the -c used to create. You can also extract only certain select files (or directories) by specifying the individual names, separated by spaces, after the tar filename, such as tar -xvf filename.tar fileA fileC

tar -xvf filename.tar

This utility, gzip (gnu zip), is used for compression. Normally, when you wish to compress a set of files, you willtar them first then compress them using this command. In doing so, the filename will automatically change from filename.tar to filename.tar.gz (appending .gz to the file extension).

gzip filename.tar

This command (g”unzip”) is used to uncompress a .tar.gz file, which will also result in the filename being changed back to filename.tar. Once it has been uncompressed, you can then untar it using the tar command above. (Alternatively, you can use gzip -d (for “decompress”) in place of gunzip.)

gunzip filename.tar.gz

This command, which uses a z switch (”zip”), allows you to take a bit of a shortcut instead of using the tar and gzip commands separately. The example will result in a compressed archive named filename.tgz.

tar -czvf filename.tgz directoryname

This command is used to uncompress and extract the files from a .tgz archive.